In the last few years there has been considerable interest among athletes in creatine, which occurs abundantly in skeletal muscle. Creatine plays a pivotal role in the regulation and homeostasis of skeletal muscle energy metabolism and it is now generally accepted that the maintenance of phospho creatine availability is important to the continuation of muscle force production. Although creatine synthesis occurs in the liver, kidney and pancreas it has been known for sometime that the oral ingestion of creatine will add to the whole body creatine pool, and it has been shown that the ingestion of 20 to 30 g creatine per day for several days can lead to a greater than 20% increase in human skeletal muscle total creatine content. Thus, WO94/02127 discloses the administration of creatine in amounts of at least 15 g (or 0.2-0.4 g/kg body weight) per day, for at least 2 days, for increasing muscular strength.
In fact, it was subsequently found that after several days of supplementation (20 g per day) with creatine in order to attain saturation, thereafter it takes no more than 2 to 3 g per day to maintain the saturation of body stores. Creatine supplementation in an appropriate dose can provide improvements to athletes involved in explosive events, which include all events lasting from a few seconds to a few minutes (such as sprinting, swimming, weight-lifting etc). Endurance performance in events lasting longer than about 30 minutes appears to be unaffected by creatine supplementation. Creatine is a normal food component and is not a drug and its use is not contrary to official regulations. The biggest benefits of supplementation can be experienced by the elderly, vegetarians or those who eat no meat or fish since these people tend to have low muscle creatine content.
Aloe Vera (Aloe barbadensis) is a member of the lily family and is a cactus like succulent plant that grows in warm frost free climates. Central American Mexican Indians used Aloe Vera for centuries as a remedy for burns, to prevent blisters, peptic and duodenal ulcers and all types of stomach and intestinal disorders, kidney infections, topical and gastric ulcers as well as to promote longevity. Today Aloe Vera is becoming very popular and its benefits are scientifically recognized.
The main use of Aloe Vera in the past has been to prevent inflammations, particularly to the skin, especially after burns, but there are many other uses. Experiments and research studies have shown that after using Aloe Vera juice, the output of the digestive enzymes and the bacterial population of the intestines are improved. Thus there has been an increasing interest in Aloe Vera as a medicament to be taken orally as people become more acquainted with its medicinal properties.
Among the several methods of presentation, there is a growing use of Aloe Vera in soft drinks which are fruit flavored, and these are quite palatable. The inclusion of creatine in a soft drink would be highly desirable because the Aloe Vera drink would be much more beneficial to health than an unsupplemented ordinary fruit drink.
Aloe Vera juice is acidic (commonly about pH3). It is well known that creatine is unstable in aqueous solutions at acid or neutral pH, and is converted into the related compound creatinine. This is highly significant as creatine has no muscle performance-enhancing effect and is excreted from the human body as a waste product in urine. In view of the foregoing, EP 0 669 083 teaches that aqueous drinks for human consumption comprising creatine must be weakly alkaline, in order to prevent the conversion of creatine into creatinine, and this has become the generally accepted opinion.
Furthermore, creatine has been used in the past only for the preparation of products with a meaty or savory flavor. For instance, Tonsheek (U.S. Pat. No. 3,615,600) discloses and is concerned with artificial flavoring mixtures which can impart a meaty flavor to foods. Similary de Rooji (U.S. Pat. No. 4,464,409) is concerned with meat flavoring. Yamazaki (JP-A-59035663) prepares a meat flavor by heating a mixture comprising creatine at pH 5.0-7.0 at temperature of 80-130.degree. C. for 30-120 minutes. Under these conditions most of the creatine would be converted to creatinine.
It would be a great advantage to present a composition for human consumption, in which the creatine therein was substantially stable, even at acidic pH and at ambient temperatures.